I see horsing around.
If you have the urge to do some energetic playing with your dog, get yourself a few nice tugs and channel his drive onto those.
The pillow is not satisfying enough for him, and inviting him to jump on you and bite you will cause you to lose in the leadership department. Hearing you squeal like prey after he bites you will cause you to lose status, as well. You need to be his leader, not his chew toy.
Check out some Michael Ellis videos on tug, channel your GSD's drive correctly. You can have lots of fun and expend your energy and his in a good way that strengthens your bond.
Norden von Narnia (Hans) DOB 1-15-2012